The comprehensive assessment of water resources has important influence on the sustainable development of society, economy and environment. Based on water poverty index, the paper setup the index system of water resources, probed some fuzzy assessment methods of water resources security based on AHP ,and comprehensively evaluated the security status of water resources in the main basins and regions of china. The results showed that the water resources poverty indexes of Yellow River, Haihe River, Huaihe River and Yangtze River basin are lower, the development potential of water resources is less, that of other 5watersheds are bigger and have certain exploitation potential of water resources. On the other hand, the evaluating results are accord with the fact of these watersheds, witch indicated that the AHP - Fuzzy evaluation model is effective, and it can offer credible hydrology evidence for water resources programming, inter-basin water transfer and hydraulic engineering operation and so on.